超高灵敏度瞬态吸收光谱仪。

Ultrahigh sensitive transient absorption spectrometer.

作者信息

Li Huang, Hu Gang, Li Bo-Han, Zeng Wen, Zhang Jingquan, Wang Xingan, Zhou Chuanyao, Ren Zefeng, Yang Xueming

机构信息

Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.

Institute of Solar Energy Materials and Devices, College of Materials Science and Engineering, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, China.

出版信息

Rev Sci Instrum. 2021 May 1;92(5):053002. doi: 10.1063/5.0048115.

DOI:10.1063/5.0048115

PMID:34243279

Abstract

Transient absorption (TA) spectroscopy is considered as a powerful technique that reflects the ultrafast dynamics of photogenerated carriers in photoelectric and photocatalysis materials. However, limited by its sensitivity, the photogenerated carrier density in TA measurements of solar energy materials is usually much higher than that in the real working condition. Here, we present a combination of kHz macro-pulse and MHz micro-pulse technique for an ultrahigh sensitive TA spectrometer, which improves the sensitivity to the 10 level of ΔOD. It enables us to study ultrafast carrier dynamics pumped by very low power, which can avoid the influence of many-body interactions and the nonlinear effect associated with high carrier density. This work provides a novel TA method with ultrahigh sensitivity, which will play an important role in investigating the carrier dynamics of semiconductors in the working condition.

摘要

瞬态吸收（TA）光谱法被认为是一种强大的技术，它能够反映光电和光催化材料中光生载流子的超快动力学。然而，受其灵敏度的限制，太阳能材料TA测量中的光生载流子密度通常远高于实际工作条件下的载流子密度。在此，我们展示了一种将kHz宏脉冲和MHz微脉冲技术相结合的超高灵敏度TA光谱仪，它将灵敏度提高到了ΔOD的10倍水平。这使我们能够研究由极低功率泵浦的超快载流子动力学，从而避免多体相互作用和与高载流子密度相关的非线性效应的影响。这项工作提供了一种具有超高灵敏度的新型TA方法，这将在研究工作条件下半导体的载流子动力学方面发挥重要作用。